Bug 1057541 part 1. Change the IDL parser to allow an optional "required" on dictionary members. r=khuey

dom/bindings/parser/WebIDL.py

@@ -4141,8 +4141,8 @@ class Tokenizer(object):
         "long": "LONG",
         "object": "OBJECT",
         "octet": "OCTET",
-        "optional": "OPTIONAL",
         "Promise": "PROMISE",
+        "required": "REQUIRED",
         "sequence": "SEQUENCE",
         "MozMap": "MOZMAP",
         "short": "SHORT",
@@ -4427,15 +4427,21 @@ class Parser(Tokenizer):
 
     def p_DictionaryMember(self, p):
         """
-            DictionaryMember : Type IDENTIFIER Default SEMICOLON
+            DictionaryMember : Required Type IDENTIFIER Default SEMICOLON
         """
         # These quack a lot like optional arguments, so just treat them that way.
-        t = p[1]
+        t = p[2]
         assert isinstance(t, IDLType)
-        identifier = IDLUnresolvedIdentifier(self.getLocation(p, 2), p[2])
-        defaultValue = p[3]
+        identifier = IDLUnresolvedIdentifier(self.getLocation(p, 3), p[3])
+        defaultValue = p[4]
+        optional = not p[1]
 
-        p[0] = IDLArgument(self.getLocation(p, 2), identifier, t, optional=True,
+        if not optional and defaultValue:
+            raise WebIDLError("Required dictionary members can't have a default value.",
+                              [self.getLocation(p, 4)])
+
+        p[0] = IDLArgument(self.getLocation(p, 3), identifier, t,
+                           optional=optional,
                            defaultValue=defaultValue, variadic=False,
                            dictionaryMember=True)
 
@@ -4633,7 +4639,7 @@ class Parser(Tokenizer):
 
     def p_AttributeRest(self, p):
         """
-            AttributeRest : ReadOnly ATTRIBUTE Type IDENTIFIER SEMICOLON
+            AttributeRest : ReadOnly ATTRIBUTE Type AttributeName SEMICOLON
         """
         location = self.getLocation(p, 2)
         readonly = p[1]
@@ -4962,6 +4968,7 @@ class Parser(Tokenizer):
                          | INTERFACE
                          | LEGACYCALLER
                          | PARTIAL
+                         | REQUIRED
                          | SERIALIZER
                          | SETTER
                          | STATIC
@@ -4972,6 +4979,13 @@ class Parser(Tokenizer):
         """
         p[0] = p[1]
 
+    def p_AttributeName(self, p):
+        """
+            AttributeName : IDENTIFIER
+                          | REQUIRED
+        """
+        p[0] = p[1]
+
     def p_Optional(self, p):
         """
             Optional : OPTIONAL
@@ -4984,6 +4998,18 @@ class Parser(Tokenizer):
         """
         p[0] = False
 
+    def p_Required(self, p):
+        """
+            Required : REQUIRED
+        """
+        p[0] = True
+
+    def p_RequiredEmpty(self, p):
+        """
+            Required :
+        """
+        p[0] = False
+
     def p_Ellipsis(self, p):
         """
             Ellipsis : ELLIPSIS